17 Oct (NucNet): The operator of the Oskarshamn nuclear station in Sweden has violated regulations by failing to submit predicted collective dose information and radiation protection actions for renovation work at Unit 2, the Swedish Radiation Safety Authority (SSM) said today.
SSM also said OKG had begun the work without authorisation. All work where the total collective dose is expected to exceed 100 person-millisieverts must be reported in advance.
SSM said it had asked OKG to investigate the incident and submit a report by 30 0ctober 2014. In the report OKG must describe the scope of the work being carried out at Unit 2, radiation protection measures that were implemented as part of the planning process, and decisions and reasons why the work was not reported to SSM.
By 21 November 2014 OKG must also submit a detailed dose prognosis for workers at the site and measures to “rectify shortcomings” in the handling of the dose prognoses.
The incident came to OKG’s attention at a meeting on 8 October 2014 when OKG said its estimate of the collective dose for the work was 4,000 person-millisieverts. SSM was told at that meeting that radiation protection planning was under way to reduce the collective dose.
Arne Johansson, an analyst at SSM, said the incident was “very serious” and OKG needs to analyse how the problem arose.
SSM did not give details of the work OKG had begun without authorisation, but said it was part of a larger project being carried out at the plant. Oskarsham-2 has been offline for a major modernisation programme that began on 1 June 2013.
OKG said in June 2014 that it had extended the modernisation programme and the restart date for the unit was “uncertain”. It was initially planned to return the unit to operation in the spring of 2015.
At the time, OKG said modernisation work in the turbine hall had been completed, as had all major mechanical installations. The focus had turned to the installation of electric power and control equipment.
Oskarshamn-2 is a 660-megawatt boiling water reactor unit which began commercial operation in 1975. There are two other commercially operational BWRs at Oskarshamn.
